org.apache.oro.text.awk

Class AwkCompiler

public final class AwkCompiler extends Object implements PatternCompiler

The AwkCompiler class is used to create compiled regular expressions conforming to the Awk regular expression syntax. It generates AwkPattern instances upon compilation to be used in conjunction with an AwkMatcher instance. AwkMatcher finds true leftmost-longest matches, so you must take care with how you formulate your regular expression to avoid matching more than you really want.

The supported regular expression syntax is a superset of traditional AWK, but NOT to be confused with GNU AWK or other AWK variants. Additionally, this AWK implementation is DFA-based and only supports 8-bit ASCII. Consequently, these classes can perform very fast pattern matches in most cases.

This is the traditional Awk syntax that is supported:

This is the extended syntax that is supported:

Since: 1.0

Version: 2.0.8

See Also: PatternCompiler MalformedPatternException AwkPattern AwkMatcher

Field Summary
static intCASE_INSENSITIVE_MASK
A mask passed as an option to the compile methods to indicate a compiled regular expression should be case insensitive.
static intDEFAULT_MASK
The default mask for the compile methods.
static intMULTILINE_MASK
A mask passed as an option to the compile methods to indicate a compiled regular expression should treat input as having multiple lines.
Method Summary
Patterncompile(char[] pattern, int options)
Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.
Patterncompile(String pattern, int options)
Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.
Patterncompile(char[] pattern)
Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);

Patterncompile(String pattern)
Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);

Field Detail

CASE_INSENSITIVE_MASK

public static final int CASE_INSENSITIVE_MASK
A mask passed as an option to the compile methods to indicate a compiled regular expression should be case insensitive.

DEFAULT_MASK

public static final int DEFAULT_MASK
The default mask for the compile methods. It is equal to 0 and indicates no special options are active.

MULTILINE_MASK

public static final int MULTILINE_MASK
A mask passed as an option to the compile methods to indicate a compiled regular expression should treat input as having multiple lines. This option affects the interpretation of the . metacharacters. When this mask is used, the . metacharacter will not match newlines. The default behavior is for . to match newlines.

Method Detail

compile

public Pattern compile(char[] pattern, int options)
Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.

Parameters: pattern An Awk regular expression to compile. options A set of flags giving the compiler instructions on how to treat the regular expression. Currently the only meaningful flag is AwkCompiler.CASE_INSENSITIVE_MASK.

Returns: A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.

Throws: MalformedPatternException If the compiled expression is not a valid Awk regular expression.

compile

public Pattern compile(String pattern, int options)
Compiles an Awk regular expression into an AwkPattern instance that can be used by an AwkMatcher object to perform pattern matching.

Parameters: pattern An Awk regular expression to compile. options A set of flags giving the compiler instructions on how to treat the regular expression. Currently the only meaningful flag is AwkCompiler.CASE_INSENSITIVE_MASK.

Returns: A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.

Throws: MalformedPatternException If the compiled expression is not a valid Awk regular expression.

compile

public Pattern compile(char[] pattern)
Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);

Parameters: pattern A regular expression to compile.

Returns: A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.

Throws: MalformedPatternException If the compiled expression is not a valid Awk regular expression.

compile

public Pattern compile(String pattern)
Same as calling compile(pattern, AwkCompiler.DEFAULT_MASK);

Parameters: pattern A regular expression to compile.

Returns: A Pattern instance constituting the compiled regular expression. This instance will always be an AwkPattern and can be reliably be casted to an AwkPattern.

Throws: MalformedPatternException If the compiled expression is not a valid Awk regular expression.

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